1. Field of the Invention
The present invention relates to a network interconnection apparatus, a network interconnection method, a name resolution apparatus and a computer program, which are for interconnecting different systems or networks. More particularly, the present invention relates to a network interconnection apparatus, a network interconnection method, a name resolution apparatus and a computer program, which are for interconnecting an external public wide area network such as a WAN or the Internet with a home private network such as a local area network (LAN).
More specifically, the present invention relates to a network interconnection apparatus, a network interconnection method, a name resolution apparatus and a computer program, which are for accessing a LAN terminal on a home private network from an external network such as the Internet. More particularly, the present invention relates to a network interconnection apparatus, a network interconnection method, a name resolution apparatus and a computer program, which are for performing a start request to a LAN terminal on a home private network from an external network such as the Internet.
2. Description of Related Art
Along with the recent popularization of the Internet, various digital contents of the network including computer files and other shave been vigorously distributed. Moreover, the development of broadband communication networks (such as an x digital subscriber line (x-DSL)), a cable television (CATV) and a wireless network is remarkable. Also in Japan, the Internet by means of broadband communication lines has been rapidly popularized to such a degree that the number of the users of the Internet using rapid broadband lines such as Asymmetric Digital Subscriber Line (ADSL) and a fiber to the home (FTTH) exceeds ten million. Under such a background, a mechanism for enabling the transmission of the distribution of rich contents such as music data, image data, digital data of electronic publications, and moving images without causing stress to a user.
Moreover, techniques of a computer and a network have deeply infiltrated into general homes recently. Home information apparatus such as a personal computer and a personal digital assistant (PDA), and various intelligent home appliances such as a television receiver and video reproducing apparatus are interconnected with each other through a home LAN. Moreover, such a home LAN is interconnected with an external wide area network such as the Internet through a router in many cases. Then, the contents duly obtained from a server on the Internet are stored in a server on the home LAN (hereinafter referred to as a “home server”), and after that the contents are distributed to the other terminals (clients) in the home through the home LAN.
The popularization of broadband networks and home LAN makes it possible to access a home personal computer or a home server from outside or a place where a user has gone, to enjoy a TV program which the user has recorded, music, a private photograph and a moving image, or to control home equipment. This is because a user can refer and operate them without feeling any stress by virtue of high speed and wide band broadband lines when the user accesses his or her home from the outside the home through the Internet. Moreover, a high speed wide band access environment called as a public wireless LAN service, which is an Internet connection environment on the outside the home, has been spread, and it is expected that server apparatuses and its services for enabling freely accessing from the outside the home to the inside the home will be popularized in the future.
However, when a person accesses and controls a home server apparatus from the outside a home, it is necessary that power sources of the home server apparatus and the other terminals connected to the home LAN are always in the on states. Unlike operations of a server for business, if the power source of the server will be constantly on state for a personal use it can be said that it is a problem from the view of the cost of electricity expenses and environments.
Techniques for remotely starting a power source of a LAN terminal were proposed in the past. However, many of them were for the use of enterprises, and the use in homes was out of sight.
For example, an inter-LAN connection apparatus for making it easy to configure a LAN by remotely controlling power sources of terminals has been proposed (see, for example, Patent Document 1). In this case, a terminal transmits a power start request to an inter-LAN connection apparatus on the other terminal side through another inter-LAN connection apparatus and a wide area network. Then, the inter-LAN connection apparatus, which has received the power start request, instructs the terminal, which is the destination of the request, the starting of the power source through a cable for operation control. According to such a procedure, the power source of a terminal in a LAN can be turned on through a wide area network.
However, in this case, it is necessary to connect the cables for operation control between the inter-LAN connection apparatus and the LAN terminals. When a LAN is configured, Ethernet (registered trademark) LAN cables is generally used, however,when dedicated cables are used for the control of the power sources, personal computers or the like as the LAN terminals should be dealt with like hardware.
Moreover, in this case, for starting a LAN terminal, firstly a LAN connection apparatus connected to a certain LAN terminal which a user wish to start with a cable for operation control is remotely logged, and then a start instruction is executed in accordance with a command. The protocol at this time is supposed to be Telnet, but it is difficult for a general consumer to perform the procedure in accordance with the Telnet protocol.
Moreover, there is known a technique called as “Magic Packet (trademark)” available from AMD Corp. in US (see, for example, Patent Document 2). The technique has a mechanism of transmitting a magic packet from a remote LAN terminal to a certain LAN terminal which a user wish to starton a LAN configured in accordance with Ethernet (registered trademark) in conformity with Institute of Electrical and Electronics Engineers (IEEE) in order to start the power source of the received LAN terminal. By means of the magic packet, there is no need of any specified cables for remotely starting a terminal.
However, the magic packet technique operates on a layer 2 network. Consequently, the magic packet cannot be transmitted via a router, and it is necessary that a LAN terminal transmitting a start instruction (a transmission source of the magic packet) and a LAN terminal receiving the start instruction (a destination of the magic packet) are on the same LAN segment. In other words, the magic packet technique does not expect a case of starting a power source from a remote terminal via a WAN of a layer 3 network over a LAN segment as the above-mentioned case of accessing a terminal in a home from the outside a home. For example, in case of via the public Internet, if a magic packet is transmitted from a remote terminal, the packet is abandoned because there is no routing information.
Moreover, when a magic packet is transmitted, some software for transmitting the magic packet is necessary to be installed in a terminal (such as a personal computer) giving a command. It is necessary to register a machine access control (MAC) address unique to the terminal to be intended to be started, the a user is obliged to perform a troublesome operation to register a MAC address composed of an alphabetic character of 12 digits manually.
Moreover, the magic packet technology does not regulate a method or a procedure for confirming whether the intended terminal to be wished to be started has really started its power source or not after the transmission of the magic packet.
[Patent Document 1] Japanese Patent Application Publication No. Hei 7-327044
[Patent Document 2] Japanese Patent Application Publication No. Hei 10-175201